The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingAir conditioning control assembly (for automatic air conditioning system)
Components
Removal
Disconnect cable from negative battery
terminal
Notice:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Remove no. 2 Instrument cluster finish
panel center ...
Installation
Hint:
Use the same procedures for the rh side and lh side.
The procedures listed below are for the lh side.
When installing the moulding, heat the vehicle body and
moulding using a heat light.
Standard heating temperature
Notice:
Do not heat the vehicle body and moulding
excessively ...
Positioning a floor jack
When raising your vehicle with a floor jack, position the jack correctly.
Improper placement may damage your vehicle or cause
injury.
Front
Rear
Caution
When raising your vehicle
Make sure to observe the following precautions to reduce the possibility of
death or serious injury:
...